CN110373542A - A kind of method of powdered biomass reduction manganese oxide ore - Google Patents

Abstract

The invention discloses a method for reducing manganese oxide ore by biomass powder. (1) Add water or dilute sulfuric acid to the manganese oxide ore powder to slurry, then slowly add concentrated sulfuric acid to the slurry, stir and react for 60-120 minutes, then add biomass powder, maintain the temperature of the reaction system, and continue to stir for 60-180 minutes After 10 minutes, the pre-reduced pulp is obtained; (2) add water or dilute sulfuric acid to the pre-reduced pulp, stir evenly and then add reducing agent to reduce for 60-120 minutes, then the manganese sulfate leaching solution can be obtained; (3) manganese sulfate After neutralization, impurity removal and solid-liquid separation of the leaching solution, manganese sulfate solution can be obtained. In summary, the present invention has the beneficial effects of overcoming the shortcomings of the existing direct reduction and leaching technology, reducing the consumption of reducing agent in the subsequent reduction process, increasing the manganese reduction rate and reduction leaching rate, reducing the amount of waste residue, and reducing the cost of manganese oxide ore leaching. .

Description

A kind of method that biomass powder reduces manganese oxide ore

technical field

The invention relates to a method for reducing manganese oxide ore by biomass powder, which belongs to the field of hydrometallurgy and chemical industry.

Background technique

Because manganese oxide ore contains a large amount of tetravalent manganese, it cannot be leached directly with sulfuric acid, which has become a difficult point in the industry.

At present, manganese oxide ore is generally reduced and roasted at a high temperature of about 850°C with solid reducing agent C or gas reducing agent (CO, H2), and the _MnO2 in it is reduced to MnO and then leached with sulfuric acid.

Its response is

Reduction roasting: MnO ₂ +C=MnO+CO

MnO ₂ +CO=MnO+CO ₂

MnO ₂ +H ₂ ＝MnO+H ₂ O

Sulfuric acid leaching: MnO+H ₂ SO ₄ ＝MnSO ₄ +H ₂ O

The reduction and roasting of manganese oxide ore requires high energy consumption, and the roasting flue gas contains solid particles, sulfur oxides, nitrogen oxides and other pollutants, which need to be treated before being discharged up to standard; in order to prevent the reoxidation of the reduced MnO in contact with air, the roasted products need to be quenched deal with. Therefore, although the reduction effect of this method is ideal, the process is complicated and the processing cost is high.

The direct reduction of acid leaching manganese oxide ore in sulfuric acid system has always been a hot spot in the industry research. The methods currently reported mainly include two-mine one-step method, SO ₂ and sulfite reduction method, biomass reduction method, organic matter reduction method, iron filings and Ferrous reduction method, etc.

The one-step method of the two mines is relatively mature, but under the condition of high initial acid concentration, S ⁰ will be produced, and a large amount of new ecological S ⁰ will be attached to the surface of the ore particles. Due to its strong hydrophobicity and non-conductivity, it hinders the formation of tetravalent manganese oxide. To carry out the reduction reaction, it is necessary to heat or increase the amount of reducing agent to obtain a satisfactory manganese leaching rate. Although the two-mine one-step method has been improved through a lot of research, it still has the disadvantages of large amount of reducing agent, long reaction time, high iron content in solution, difficulty in removing iron and large amount of slag, which limits its popularization and application.

The SO ₂ and sulfite reduction methods have high requirements on the control of the pH value of the system, the pH value is low, and the utilization rate of the reducing agent is low; The quality of manganese solution has a certain influence.

Biomass reduction method has a wide range of reducing agents, but the reaction time is long, and a large amount of organic matter remains in the solution after leaching, which is difficult to remove.

Organic matter reduction methods such as formaldehyde, methanol, oxalic acid, aniline, benzyl alcohol, glucose, etc. have a high manganese leaching rate, but due to the high cost of the reducing agent, the actual production is unacceptable.

To sum up, the maturity of the direct reduction leaching technology of manganese oxide ore is not yet able to meet the actual production needs. The main reason is that it is difficult to directly reduce the tetravalent manganese in the manganese oxide ore to the divalent manganese oxide ore. Pre-reduction of the manganese oxide ore will reduce a large amount of tetravalent manganese to trivalent, and further reduce the diameter of the ore particles and increase the specific surface area of the reaction. It can minimize the difficulty of subsequent reduction, not only increase the reduction speed, but also greatly reduce the consumption of reducing agent.

Contents of the invention

The object of the present invention is to provide a method for reducing manganese oxide ore by biomass powder. The invention has the characteristics of overcoming the shortcomings of the existing direct reduction and leaching technology, reducing the consumption of reducing agent in the subsequent reduction process, increasing the manganese reduction rate and reduction and leaching rate, reducing the amount of waste residue, and reducing the cost of manganese oxide ore leaching.

Technical scheme of the present invention: a kind of method of biomass powder reduction manganese oxide ore, comprises the following steps:

(1) Add water or dilute sulfuric acid to the manganese oxide ore powder to make slurry, then slowly add concentrated sulfuric acid to the slurry, stir and react for 60-120 minutes, then add biomass powder, maintain the temperature of the reaction system, continue to stir and react for 60-180 minutes Minutes later, the pre-reduced pulp is obtained;

(2) Add water or dilute sulfuric acid to the pre-reduced ore pulp, stir evenly, add reducing agent after reducing for 60-120 minutes, both can make manganese sulfate leaching solution;

(3) Manganese sulfate solution can be obtained by neutralizing, removing impurities, and separating solid and liquid from the manganese sulfate leaching solution.

In the aforementioned method for reducing manganese oxide ore by biomass powder, in the step (1), the manganese oxide ore includes pyrolusite, manganese nodules, electrolytic manganese anode slag, ore/dust and slag containing manganese dioxide.

In the aforementioned method for reducing manganese oxide ore by biomass powder, in the step (1), the manganese oxide ore powder is slurried by adding water or dilute sulfuric acid at a solid-to-liquid ratio of 1:0.5-2.

In the aforementioned method for reducing manganese oxide ore by biomass powder, in the step (1), concentrated sulfuric acid is slowly added to the slurry liquid so that the concentration of sulfuric acid in the slurry liquid is greater than or equal to 650 g/l.

In the aforementioned method for reducing manganese oxide ore with biomass powder, in the step (1), the biomass powder is one or more of rice straw powder, straw powder, chaff powder, and flour, and the particle size of the powder is ≥100 mesh, The added amount of the biomass powder is 2-10% of the manganese mass.

In the aforementioned method for reducing manganese oxide ore by biomass powder, in the step (1), the temperature of the reaction system is maintained to be greater than 333K.

In the aforementioned method for reducing manganese oxide ore by biomass powder, in the step (2), water or dilute sulfuric acid is added to the pre-reduced pulp at a solid-to-liquid ratio of 1:0.5-2.

In the aforementioned method for reducing manganese oxide ore by biomass powder, in the step (2), the reducing agent is one or both of oxalic acid, hydrogen peroxide, and glucose.

Compared with the prior art, the present invention has the following beneficial effects:

Manganese oxide ore powder is slurried by adding water or dilute sulfuric acid at a solid-to-liquid ratio of 1:0.5-2, and adding concentrated sulfuric acid to the slurry to make the concentration of sulfuric acid in the slurry ≥ 650g/l. This process releases a lot of heat to maintain the system reaction When the temperature is higher than 333K, continue to stir for 60-120 minutes before adding biomass powder. The biomass powder is added according to 3-10% of the manganese mass. In order to improve the reaction efficiency, the particle size of the biomass powder needs to be finely ground to ≥100 mesh. In this reaction system, the particle size of biomass powder is closely related to the reaction speed, powder dosage and acid consumption. The smaller the powder particle size, the faster the reaction speed, the shorter the reaction time, and the less powder dosage required. consumption is lower.

The cellulose in the biomass powder reacts with concentrated sulfuric acid to form hemicellulose, which further reacts to produce a large amount of new particulate carbon and some compounds with aldehyde groups, and at the same time releases a large amount of heat to maintain and further increase the temperature of the reaction system. The diameter of the newly formed particulate carbon particles is nano-scale, has a large specific surface area and chemical reactivity, and is evenly dispersed into the solution system under constant stirring. The nascent nano-carbon and aldehyde-based substances react with MnO2 in manganese oxide ore, and the manganese in it is reduced from tetravalent to trivalent or divalent. The reaction formula is as follows:

2MnO ₂ +2H ₂ SO ₄ +C＝2MnSO ₄ +2H ₂ O+CO ₂

(CH _x O _y )+mMnO ₂ +mH ₂ SO ₄ →mSO4+mCO2+mH ₂ O

Not only that, under the action of complex system catalysis and temperature, MnO ₂ will partially undergo auto-redox reaction, and part of tetravalent manganese will be transformed into trivalent manganese. The temperature of the reaction system is kept higher than 333K, and the stirring reaction is continued for 60-180 minutes to complete the pre-reduction process of manganese oxide ore. The manganese oxide ore pre-reduction slurry obtained by the reaction is easy to be quickly reduced by a large amount of reducing agent, and a good manganese leaching rate can be obtained.

Add water or dilute sulfuric acid to the pre-reduced pulp, stir evenly, add a reducing agent for further reduction for 60-120 minutes, and manganese sulfate leaching solution can be obtained, and manganese sulfate can be obtained after the leaching solution is neutralized, impurity-removed, and solid-liquid separation solution.

The process of formation of nascent particulate carbon can also be produced outside the reaction system through the action of biomass powder and concentrated sulfuric acid and then added to the reaction system, and its function and effect are consistent.

Oxidized ores suitable for pre-reduction in the present invention include ores, dusts and slags containing manganese dioxide such as pyrolusite, hard manganese ore, black manganese ore, brown manganese ore, manganese nodules, manganese anode slag, and manganese alloy dust.

The invention overcomes the shortcomings of the existing direct reduction leaching technology, such as large consumption of reducing agent, long leaching time, low leaching rate, large amount of slag, and high leaching cost, and can reduce the consumption of reducing agents such as glucose, hydrogen peroxide, and oxalic acid by 40-50%. , improve the manganese reduction rate, the manganese leaching rate is greater than or equal to 98%, reduce the amount of waste residue, and reduce the leaching cost of manganese oxide ore.

In summary, the present invention has the beneficial effects of overcoming the shortcomings of the existing direct reduction leaching technology, increasing the manganese reduction rate and reduction leaching rate, reducing the amount of waste residue, and reducing the cost of manganese oxide ore leaching.

Detailed ways

The present invention will be further described below in conjunction with the examples, but not as a basis for limiting the present invention.

Example 1:

(1) Get 1000g pyrolusite powder (Mn=40%), add 500ml dilute sulfuric acid for slurrying, slowly add 1000ml concentrated sulfuric acid in the slurrying liquid after stirring, add 12g chaff powder after stirring for 60mim, the powder particle size is 200 In order to maintain the temperature of the reaction system above 333K, stir the reaction for 60 minutes to prepare the pre-reduced pulp. Add 3000ml of water to the pre-reduced pulp, slowly add 70g of glucose to reduce and react for 120min to obtain a leachate, and the leachate is neutralized, impurity removed, and solid-liquid separated to obtain a manganese sulfate solution. The concentration of Mn ²⁺ in the solution is 85.2g/l.

(2) Get 1000g pyrolusite powder (Mn=40%), add 800ml water slurry, stir slowly in the slurry liquid after adding 1500ml concentrated sulfuric acid, add 40g straw powder after stirring for 120mim, the powder particle size is 100 orders, Maintain the temperature of the reaction system above 333K, and stir for 180 minutes to prepare the pre-reduced pulp. Add 5000ml of water to the pre-reduced pulp, and slowly add 90g of oxalic acid for reduction reaction for 60 minutes to obtain a leachate. The leachate is neutralized, impurity removed, and solid-liquid separated to obtain a manganese sulfate solution. The concentration of Mn ²⁺ in the solution is 50.6g/l.

(3) Get 1000g pyrolusite powder (Mn=40%), add 2000ml water slurry, after stirring, slowly add 2000ml concentrated sulfuric acid in the slurry solution, add 35g straw powder after stirring for 60mim, the powder particle size is 120 orders, The temperature of the reaction system is kept higher than 333K, and the reaction is stirred for 150 minutes to prepare the pre-reduced pulp. Add 2000ml of water to the pre-reduced pulp, slowly add 150ml of hydrogen peroxide (30%) and reduce it for 100min to obtain a leachate. The leachate is neutralized, impurity removed, and solid-liquid separated to obtain a manganese sulfate solution. The concentration of Mn2 ⁺ in the solution is 60.8 g/l.

(4) Get 1000g manganese nodule ore powder (Mn=30%), add 900ml dilute sulfuric acid slurry, stir slowly in slurry liquid, add 1200ml vitriol oil slowly, add 25g chaff powder after stirring reaction 80mim, powder particle size is 300 mesh, keep the temperature of the reaction system higher than 333K, and stir for 120 minutes to prepare the pre-reduced pulp. Add 2000ml of water to the pre-reduced pulp, and slowly add 70ml of hydrogen peroxide (30%) to reduce for 120 minutes to obtain a leachate. The leachate is neutralized, impurity removed, and solid-liquid separated to obtain a manganese sulfate solution. The Mn2 ⁺ concentration of the solution is 69.7 g/l.

(5) Get 1000g of manganese nodule ore powder (Mn=30%), add 1000ml of dilute sulfuric acid to slurry, stir well and then slowly add 1200ml of concentrated sulfuric acid to the slurry solution, add 40g of rice straw powder after stirring for 100mim, the powder particle size is 300 In order to maintain the temperature of the reaction system above 333K, stir the reaction for 150 minutes to prepare the pre-reduced pulp. Add 1500ml of water to the pre-reduced pulp, slowly add 60g of glucose and reduce for 120min to obtain a leachate. The leachate is neutralized, impurity removed, and solid-liquid separated to obtain a manganese sulfate solution. The concentration of Mn ²⁺ in the solution is 77.6g/l.

(6) Get 1000g of electrolytic manganese anode slag (Mn=44%), add 500ml of dilute sulfuric acid for slurrying, and after stirring evenly, slowly add 600ml of concentrated sulfuric acid in the slurrying liquid, add 20g of flour powder after stirring for 60mim, the powder particle size is 200 In order to maintain the temperature of the reaction system above 333K, stir and react for 70 minutes to prepare the pre-reduced pulp. Add 3000ml of water to the pre-reduced pulp, slowly add 90g of glucose and reduce for 120min to obtain a leachate. The leachate is neutralized, impurity removed, and solid-liquid separated to obtain a manganese sulfate solution. The concentration of Mn ²⁺ in the solution is 102.2mg/l.

(7) Get 1000g electrolytic manganese anode slag (Mn=44%), add 800ml dilute sulfuric acid to slurry, slowly add 900ml vitriol oil in the slurry liquid after stirring, add 50g chaff powder after stirring reaction 90mim, powder particle size is 100 mesh, keep the temperature of the reaction system higher than 333K, and stir for 180 minutes to prepare the pre-reduced pulp. Add 3000ml of water to the pre-reduced pulp, slowly add 75g of oxalic acid for reduction for 60 minutes, and obtain leachate. The leachate is neutralized, impurity removed, and solid-liquid separated to obtain a manganese sulfate solution. The concentration of Mn ²⁺ in the solution is 90.1mg/l.

(8) Take 1000g of electrolytic manganese anode slag (Mn=44%), add 700ml of dilute sulfuric acid to slurry, stir evenly, slowly add 1200ml of concentrated sulfuric acid to the slurry, add 40g of straw powder after stirring for 60mim, the powder particle size is 200 In order to maintain the temperature of the reaction system above 333K, stir and react for 160 minutes to prepare the pre-reduced pulp. Add 3000ml of water to the pre-reduced pulp, slowly add 120ml of hydrogen peroxide (30%) and reduce for 120min to obtain a leachate, the leachate is neutralized, impurity removed, and solid-liquid separated to obtain a manganese sulfate solution. The concentration of Mn2 ⁺ in the solution is 83.6 mg/l.

Claims (8)

1. a kind of method of powdered biomass reduction manganese oxide ore, it is characterised in that: include following steps:

(1) manganese oxidation miberal powder is first added into water or dilute sulfuric acid pulp, is then slowly added to the concentrated sulfuric acid into pulp liquid, is stirred to react Powdered biomass is added after 60-120 minutes, maintains temperature of reaction system, continues after being stirred to react 60-180 minutes, obtain pre- Restore ore pulp；

(2) water or dilute sulfuric acid are added into prereduction ore pulp, after being stirring evenly and then adding into reducing agent reduction 60-120 minutes, both may be used Manganese sulfate leachate is made；

(3) manganese sulfate leachate is neutralized, removal of impurities, is separated by solid-liquid separation, and can be prepared by manganese sulfate solution.

2. the method for powdered biomass reduction manganese oxide ore according to claim 1, it is characterised in that: the step (1) In, manganese oxide ore includes pyrolusite, manganese nodule, electrolytic manganese anode slag, mine/dust and slag containing manganese dioxide.

3. the method for powdered biomass reduction manganese oxide ore according to claim 1, it is characterised in that: the step (1) In, manganese oxidation miberal powder is added into water or dilute sulfuric acid pulp by solid-to-liquid ratio 1:0.5-2.

4. the method for powdered biomass reduction manganese oxide ore according to claim 1, it is characterised in that: the step (1) In, it is slowly added to the concentrated sulfuric acid into pulp liquid, makes sulfuric acid concentration >=650g/l in pulp liquid.

5. the method for powdered biomass reduction manganese oxide ore according to claim 1, it is characterised in that: the step (1) In, powdered biomass be one or more of straw powder, stalk powder, husk powder, flour, powder size >=100 mesh, Its powdered biomass additional amount is the 2-10% of manganese quality.

6. the method for powdered biomass reduction manganese oxide ore according to claim 1, it is characterised in that: the step (1) In, maintain temperature of reaction system to be greater than 333K.

7. the method for powdered biomass reduction manganese oxide ore according to claim 1, it is characterised in that: the step (2) In, water or dilute sulfuric acid are added into prereduction ore pulp by solid-to-liquid ratio 1:0.5-2.

8. the method for powdered biomass reduction manganese oxide ore according to claim 1, it is characterised in that: the step (2) In, reducing agent is one or both of oxalic acid, hydrogen peroxide, glucose.